NEW YORK, March 1 (Reuters) - U.S. natural gas trade groups said on Thursday they are concerned that new U.S. steel import tariffs could delay or reduce new pipeline projects as well as dent exports of liquefied natural gas.

* U.S. President Donald Trump said on Thursday the United States will impose tariffs of 25 percent on steel imports and 10 percent on imported aluminum next week.

* The type of pipe and the steel used to make large diameter, thick-walled pipe used for interstate natural gas pipeline projects are niche products that are not available off the shelf or even from a wide variety of manufacturers, a spokeswoman for the Interstate Natural Gas Association of America said in an emailed statement.

* The delays or reduction would be unfortunate, particularly given that ICF, a consulting group, estimates that about three quarters of current pipeline construction expenditures (including material purchases) end up in the pockets of American workers and business owners, the INGAA spokeswoman said.

* INGAA is the North American association representing the interstate and interprovincial natural gas pipeline industry and has members including Kinder Morgan Inc, ONEOK Inc and EQT Corp.

* Separately, a trade group representing LNG companies expressed concern that the Trump Administration's plan to impose tariffs on steel could have the "unintended effect of endangering much-needed U.S. LNG export projects." (Reporting by Devika Krishna Kumar and Scott DiSavino in New York, editing by G Crosse)